This project examines the function of the salivary glands and other oral tissues in individuals with alterations of normal oral function due to disease or therapeutic procedures. Major efforts have been directed at the evaluation of patients complaining of xerostomia (oral dryness). Entry into all studies is through the Dry Mouth Clinic. Utilizing outpatient and inpatient services, specific evaluative and diagnostic approaches have been developed to aid in establishing the extent and causes of salivary gland dysfunction in the "dry mouth" patient. Major patient groups studied include individuals with Sjogren's syndrome, an autoimmune exocrinopathy, and those with salivary hypofunction secondary to therapeutic irradiation to the head and neck region. Oral and secretory effects of a number of other systemic diseases also are evaluated. Ongoing treatment protocols are evaluating the effectiveness of the parasympathomimetic drug pilocarpine for salivary stimulation in the post-radiation group and a combination of an anti-inflammatory drug and pilocarpine for Sjogren's syndrome patients. Clinical and laboratory studies focusing on the immunological basis of the salivary component of Sjogren's syndrome have advanced and represent the main focus of our work. Markers of salivary gland disease activity in the serum of patients with Sjogren's syndrome have been identified. The effects of cytokines and other immune mediators on a cultured human salivary cell line have been investigated. Work has begun on an in vivo animal model system for inflammatory salivary gland disease using an immunodeficient mouse strain.